Causes of death of patients with methamphetamine dependence: A record-linkage study

Introduction and Aims. Methamphetamine use leads to increased likelihood of premature death. The authors investigated the causes of death and risk of mortality in a large cohort of patients with methamphetamine dependence. Design and Methods. A cohort of 1254 subjects with methamphetamine dependence, admitted to a psychiatric centre in Taiwan from January 1990 to December 2007, was retrospectively studied. Diagnostic and sociodemographic data for each subject were extracted from the medical records based on a chart review process. Mortality data were obtained by linking to the National Death Certification System and standardised mortality ratios (SMRs) were estimated. The risk and protective factors for all-cause deaths were explored by means of survival analyses. Results. During the study period, 130 patients died. Of them, 63.1% died unnatural deaths, while the remaining 36.9% died natural deaths. The 1year cumulative rates for unnatural and natural deaths were 0.018 and 0.006, respectively, and the 5year rates were 0.046 and 0.023, respectively. The cohort had excessive mortality (SMR=6.02), and women had a higher SMR for unnatural deaths than men (26.19 vs. 9.82, P=0.001). For all-cause deaths, comorbidity with other substance use disorders was associated with increased risk of death, despite that being married was associated with a reduced risk. Discussion and Conclusions. A substantial proportion of the deceased died natural deaths, but most died unnatural deaths. The findings show significant evidence to provide valuable insight into premature deaths among methamphetamine-dependent users. This information is valuable for development of prevention and intervention programs.